The ankle-brachial index (ABI) is a simple, non-invasive test used to measure the ratio of the blood pressure in the lower legs to the blood pressure in the arms. This ratio is used to assess the presence of peripheral artery disease (PAD), which is a condition where the arteries in the legs or arms are narrowed or blocked.

Procedure:

1. Measurement of Blood Pressure:
   • Blood pressure cuffs are placed on both arms and ankles.
   • Doppler ultrasound devices are used to measure systolic blood pressure at the brachial artery (in the arm) and at the arteries in the ankles.
2. Calculation:
   • The ABI is calculated by dividing the systolic blood pressure at the ankle by the systolic blood pressure in the arm.

Uses:

• Diagnose PAD: Identify the presence and severity of peripheral artery disease.
• Assess Cardiovascular Risk: Evaluate the risk of cardiovascular events such as heart attacks or strokes.

Monitor Treatment: Track the effectiveness of treatments for PAD.